Establishment Of High Effcient Regeneration System And Induction And Selection Of Salt-tolerance Mutant Of Sweetpotato In Vitro

In this research, the high efficient regeneration system of sweetpotato cultivar was established by using three types of explants, stem segment, stem leaves and leafstalk ; the screening techniques for salt tolerance and mutants of four sweetpotato stem segment callus and asepsis seeding in vitro were studied, they were irradiated with 60Co gamma ray and filtrate research, and primary screening system for salt tolerance evaluation was established. The primary content and result are as follows:1. Regeneration medium of sweetpotato was screening. By using the orthogonal test, screen out the optimal medium for callus induction was MS+1.0mg/L NAA +0.5mg/L BA, and stem segment was the optimal explant.2. The optimal regeneration medium for callus were MS+0.02 mg/L 2,4-D+1.0 mg/L KT. Adding silver nitrate into optimal regeneration medium to callus differentiation, elevated the polarization rate, and the bud clumps were induced, the optimal content of silver nitrate is 4 mg/L.3. The optimum dose of 60Co-γrays treatment on callus induction of sweetpotato is 80 Gy. The mutants were tolerant 1.5% NaCl, increased by 0.5% than that of contrast sample. After primary selection from critical content of NaCl, the induced mutants could resist salt stress by increasing content of free proline,and decreasing content of MDA, and Chlorophyll. The salt tolerance of induced mutation was higher that of control. Salt tolerant tests in vitro revealed that the mutants possessed salt tolerance and had genetic stability.